The present invention relates to a high power and high speed linear motor. A particularly economical linear motor is already known comprising rectangular for example square coils separated by magnetic strips around a core which is equally square or rectangular and an armature of U or approximately U-shape which encloses the prismatic bar thus formed. This motor of particular geometry has been developed under the name of an axial motor.
As regards their inductive part, conventional electrical motors, whether rotary or linear, are always designed with a magnetic circuit able to receive the electrical winding. To this end, it may be provided either with teeth or, as in axial motors, it may have a structure which leaves room for the coils between the magnetic parts.
Naturally, the conducting parts must be insulated and since they are the cause of considerable heating, they must be cooled. A fine structure which combines electrical and magnetic parts, taking these two imperatives into account, firstly leads to considerable wastage of space and secondly introduces a limitation in the cooling power. Nevertheless, this is normally accepted owing to the necessity of passing the magnetic flux through the windings.
High power and high speed motors have a special construction in this respect because they are well-suited to the large gaps between the parts of the magnetic circuit which constitute the armature on the one hand and the inductor on the other hand. From another point of view, they pose particularly acute problems of cooling, linked with the fact that they are subject to frequent starting.